The present invention is in a method for regulating the pressure of a gas produced in a reactor and continuously withdrawn from the reactor by a gas compressor which is in a gas withdrawal path.
Closed reactors, such for example as industrial furnaces of large volume for the production of calcium carbide, or large mixing appliances in which chemical reactions with gas generation proceed, are dependent in their operation upon numerous influencing values (Winnacker-Kuchler, 4th edition, vol. 2, pp. 611 et seq., 1982). Therefore they are frequently subjected to major pressure fluctuations which are caused by irregular gas generation and also spontaneous gas eruptions from the reaction zone of the charge. Large pressure fluctuations cause disturbances in the reactor operation, and also undesirably influences the gas withdrawal.
According to the prior art the gas withdrawal takes place out of closed reactors through a gas compressor which follows a gas preparation plant. The gas delivery is kept largely constant by a regulating circuit inertly responding to the reactor pressure with a by-pass valve as an adjusting member connecting the suction side with the delivery side of the gas compressor By way of example, a slowly occurring pressure rise in a reactor is evened out by closure of the by-pass valve and thus increase of the delivery of the gas compressor.
Rapid pressure variations appearing due to peaks of positive or negative pressure cannot be compensated by the inertly responding regulating circuit. Therefore dangerous gas can escape into the environment from such reactors, since a sudden pressure increased therein, caused by a spontaneous emergence of relatively large gas quantities from the reaction zone, can be brought down only slowly.
On account of the inertia of the regulating section, a rapid pressure rise in the reactor still effects a slowly rising delivery of the gas even when the pressure in the reactor again reaches its ideal value. Over-controlling occurs resulting in the development of a negative pressure in the reactor chamber. Thus undesired external air is sucked into the reactor chamber.
Such problems can endanger the personnel and lead to considerable losses of yield and energy. Furthermore the function of the gas preparation plant connected to the reactor is persistently influenced in an undesired manner by suddenly occurring fluctuations of pressure and quantity of the gas.